With the development of more sophisticated electronic components, systems are subject to increasingly demanding power density levels. The heat generated during operation of these components can degrade the performance and reliability of the overall system and can even cause system failure. Thus, thermal management is an important element of the design of electronic products as both performance reliability and life expectancy of electronic equipment are inversely related to the chip junction temperature of the equipment.
Contemporary aircraft use avionics to control the various equipment and operations for flying the aircraft. The avionics may be stored in an avionics chassis that protects the avionics from harsh environment conditions, including electrically shielding the avionics from electromagnetic interference (EMI), protecting the avionics from lightning strikes, dissipating the heat generated by the avionics.
Thermal management of electronics is a key element in electronics including, but not limited to, avionics, mining and transportation systems, especially in the event of loss of air cooling or in the event of sudden spikes in power. A reduction in overall thermal resistance of the system including the card and the chassis may be obtained by enhancing heat extraction, spreading, and convection techniques to dissipate the heat from the chip to the ambient using heat pipes, fin optimization for natural convection and forced convection techniques. The transient thermal response of a system is function of the heat input and the thermal resistance and capacitance of a system. In aviation electronics, higher thermal mass is sometimes used to achieve a stable thermal response to a changing boundary condition using a large heat sink. Phase change materials (PCM) such as waxes can be used as alternative to absorb dissipated thermal energy. Contrary to large heat sinks, PCMs employ a change in phase of a substance from solid to liquid or liquid to gaseous to absorb the heat. By using this latent heat absorption, PCMs are significantly more effective in theory at absorbing heat from electronics. However, the low thermal conductivity of PCMs has limited their applicability as it results in ineffectiveness in getting the heat in and out of a PCM material. In other research, thermal conductivity of the phase change materials are increased by the use of higher thermal conductivity additives. In other approaches the energy storage is used approach as system and a system is developed around the PCM. This PCM system can include use of simple metal fins submerged in the PCM and use of metal foams. While the use of heat transfer enhancement structures lower thermal resistance of the PCM system, only additives increase the thermal conductivity of the PCM. These PCM based thermal energy storage system approaches are applied to increase the surface contact area and hence increase “effective” thermal conductivity or reduce resistance.